/Engine/Source/Runtime/Slate/Public/Framework/Text/CharRangeList.h
Initializes this range from the given substring. See ToString for an overview on the required format. OutLastIndex will contain the index of the character following the parsed range.
bool InitializeFromString ( const [FString](API\Runtime\Core\Containers\FString) & InDefinitionString, int32 InFromIndex, int32 * OutLastIndex )